batman-adv: Prefix gateway-client non-static functions with batadv_

batman-adv can be compiled as part of the kernel instead of an module. In that
case the linker will see all non-static symbols of batman-adv and all other
non-static symbols of the kernel. This could lead to symbol collisions. A
prefix for the batman-adv symbols that defines their private namespace avoids
such a problem.

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
diff --git a/net/batman-adv/gateway_common.c b/net/batman-adv/gateway_common.c
index 6e3b052..a0b0f52 100644
--- a/net/batman-adv/gateway_common.c
+++ b/net/batman-adv/gateway_common.c
@@ -165,7 +165,7 @@
 	if (atomic_read(&bat_priv->gw_bandwidth) == gw_bandwidth_tmp)
 		return count;
 
-	gw_deselect(bat_priv);
+	batadv_gw_deselect(bat_priv);
 	bat_info(net_dev,
 		 "Changing gateway bandwidth from: '%i' to: '%ld' (propagating: %d%s/%d%s)\n",
 		 atomic_read(&bat_priv->gw_bandwidth), gw_bandwidth_tmp,